Disappointing growth of Japan's economy in the second quarter weighed the markets down to a lower open with the Dow losing 41 points to 13,166. Nasdaq slipped 7 points to 3013.On the upside

Shares of Groupon (Nasdaq: GRPN) continued rising ahead of its earnings release after market close. Tesoro (NYSE: TSO) will pay approximately $2.5 billion to acquire BP's Southern California refinery and marketing business.Elan (NYSE: ELN) will spin-off its discovery science and Neotope Biosciences into a separate independent, publicly traded company.On the downsideKnight Capital Group (NYSE: KCG) extended its losses.Standard & Poor's downgraded the credit rating of Thompson Creek Metals (NYSE: TC) from a B- to a CCC+ on Friday.Goldman Sachs analyst Judy Hong downgraded Coca-Cola (NYSE: KO) to a Neutral rating due to slowing growth and rising competition.In the broad market, declining issues outpaced advancers by a margin of nearly 5 to 4 on the NYSE and by 9 to 7 on Nasdaq. The Russell 2000 which tracks small cap stocks eased a point to 800.